There are plenty of places you can find Pi easily on this blog, but you might be surprised as to where you can find Pi hidden, if you just look close enough. I'll start with a few of the easier places to find it.

Over on Twitter, user 3point141592653 is tweeting pi. As this writing, the tweets are only up to 290 digits, but there's more than enough material to suggest that many more entries are to come.

Back in September of 2007, I posted the following animation from Wikipedia where it seems Pi's presence would appear quite obvious. However, Pi was also ingeniously hidden in the picture itself in at least 2 ways. The ratio of the width to the length is equal to Pi to the first decimal place - 3.1 (if the picture was only 1 picture wider, it could've been accurate to 2 decimal places). Also, the final frame is held for exacty 3.14 seconds.

A calculator such as the Windows calculator is also a seemingly obvious place to find Pi, but there's even a hidden side there. Ever since Windows 98, if you copy the word pi from a document, and then paste it into the calculator, you get Pi to 32 decimal places!

Those of you who use iGoogle as your homepage, and have set it up with their custom themes, have probably noticed that the themes often change based on the time of day. What far fewer people know is that the geeks at Google, with a math-based sense of humor, have set up a special version of many of the themes that activates only at 3:14 AM, as discussed a few years ago over at DownloadSquad. Google itself has some nice screenshots of the special 3:14 AM versions of the theme.

In the same episode, Charlie meets Mildred in the garden, where she's reading The Life of Pi, and Charlie explains a concept using the example of items in a refrigerator, the last example of which is pie.

Of course, the list of software with hidden Pi references, in everything from mIRC to Guitar Hero II, but it doesn't stop there. You can find them in some surprising places.

If you're a fan of the band Travis, who themselves are big fans of Pi, check out their album The Man Who. The CD lists 10 tracks, but there's a hidden one, titled Flashing Blue Light, that starts exactly 3 minutes and 14 seconds after the last track.

Probably the strangest place to find hidden examples of Pi is in subway stations. Are you having an emergency while traveling in the Buenos Aires subway system? Just dial *31416! However, an even more subtle and beautiful subway example of hidden Pi is the Downsview subway station in Toronto. There's a mural that seems to be a random blend of colors, but it's actually Pi ingeniously disguised.

Have you ever spotted hidden examples of Pi anywhere? Let me and everyone else hear about it in the comments!